Seated occupant impact-injury minimizing method

ABSTRACT

A shock-load G-force minimizing seat structure and injury-minimizing methodology wherein the seat structure responds principally in non-springy compression, rather than in spring-loading bending, to vertically directed shock loads. The seat structure features an anti-springy frame structure which supports a thin and very lightweight seat cushion support spanner web formed preferably of a non-stretchy material, such as a material made out of elongate carbon-fiber strands.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a division, and claims the priority filingdate, of co-pending application Ser. No. 10/426,103, filed Apr. 29, 2003for invention of Michael R. Dennis for “Seat Structure with Anti-SpringSpanner Element”. The entire contents of that co-pending application arehereby incorporated herein by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] This invention pertains to seat structure, and in particular tomethodology associated with anti-spring, web spanner structure forsupporting an occupant-seating cushion in seat structure designed foruse in the setting of high-speed vehicle, such as an aircraft, tominimize injuries in hard and/or catastrophic impact events. The methodof the invention also pertains to the use of such seat structure whichfurther includes an anti-spring, compression-load seat-base structure.

[0003] Conventional seat design, insofar as it has been aimed atminimizing injuries caused from a hard “bottoming-out” event, such as ina crash landing in an aircraft, have typically introduced structuralarrangements which, unfortunately, and to some extent accidentally, tendto exacerbate the impact-injury problem. Such design often utilizes acollapsing or “stroking” behavior in an effort to minimize the totalload delivered to a seat occupant. This approach, however, frequentlyintroduces undesirable weight, complexity, and expense issues, and alsoadditionally enhances “springiness” in a seat structure—a situation thatcan actually lead to an amplification of damaging accelerations appliedto a seat occupant's spine. Increased springiness, counter-intuitive asthis may seem, introduces an enlarged rebound counter-accelerationfractions of a second after a dangerous impact occurs, and suchincreased counter-acceleration significantly contributes to serious, andoften fatal, injury.

[0004] The methodology of the present invention addresses this issuewith an innovative seat structure which, in use, is interposed a seatoccupant and a vehicle frame, such as an aircraft frame, and whichpossesses substantially no spring-loading and spring-back behavior. Thisseat structure, disclosed in the environment of an aircraft, and in apreferred and best mode embodiment and manner of use which arespecifically illustrated and described herein, features a very thin,occupant-cushion-supporting spanner web formed of substantiallynon-stretchy and non-springy strand material, such as elongate carbonfiber, or Kevlar®, strand material, which is deployed under very modesttension between a pair of transverse, spaced, parallel, elongate andvery robust cylindrical tubes. These tubes are carried on an adjustable,selectively fore and aft repositionable, slider sub-frame which, inturn, rides slideably on a pair of spaced, lateral and parallelI-beam-like rails (seat-frame substructures) which are, effectively,directly anchored to the aircraft frame. The mechanism furnished forenabling selectable slide repositioning, and positional unlocking andlocking associated with this capability, do not form any part of thepresent invention, and are neither described nor illustrated herein.

[0005] These components of the seat frame—tubes, slider mechanism, railsand associated structures—load principally in very modest-deflectioncompression, rather than in bending, and consequently make an importantcontribution to the non-spring-back performance of the entireseat-structure. The spanner web, non-stretchable as it is, offers anextremely light weight, thin-format direct cushion support structurewhich also specially exhibits substantially no spring-loading,spring-back response to loading activity, such as an impact-producedsharp, high-level accelerative loading.

[0006] These and other features and advantages which are offered by thepresent invention will become more fully evident and appreciated as thedescription that now follows is read in conjunction with theaccompanying drawings.

DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 presents an isometric, side-frontal view of a preferred andbest mode embodiment of seat-structure constructed in accordance withthe invention. FIG. 1 includes a fragmentary illustration of anaircraft's frame structure with respect to which this seat-structure isanchored.

[0008]FIG. 2 gives a larger-scale, top-plan view (with seat-backstructure removed) of what is shown in FIG. 1.

[0009]FIGS. 3-5, inclusive, each present an even larger-scale,fragmentary view (partially cross-sectional) of structural details takenalong the lines 3-3, 4-4, and 5-5, respectively, shown in FIG. 2.

[0010]FIG. 6 presents three, story-telling, isometric views whichdescribe, at least in part, assembly of the cushion-supporting spannerstructure which is employed in the seat structure of the presentinvention.

[0011]FIG. 7 is a simplified fragmentary detail illustrating onemodified form of the invention.

[0012]FIG. 8 is a fragmentary cross section taken generally along theline 8-8 in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

[0013] Turning now to the drawings, and referring first of all to FIGS.1-5, inclusive, shown generally at 10 is a preferred and best-modeanti-spring-back seat structure which is constructed for operation inaccordance with the present invention. Very specifically, thisillustrated seat-structure is constructed in accordance with a preferredand best mode embodiment of and manner of practicing the invention.Illustrated fragmentarily at 12 is structure that represents an aircraftframe with regard to which seat-structure, or seat, 10 is suitablerigidly anchored.

[0014] Seat 10 includes a non-springy, rigid frame 14, and mountedthereon, as will be described, a thin, nominally flexible, substantiallyunstretchable spanner web 15 of material which is intended to support anappropriate, direct occupant-supporting cushion which is shown at 16 inFIG. 1. The design and construction of this cushion form no part of thepresent invention, but preferably, cushion 16 is made of a somewhat“soft” material which does not possess a springy nature.

[0015] Frame 14 includes lower and upper sub-frames 20, 22 respectively,which are functionally united, in the region designated 24, for selectedfore-and-aft relative positional sliding and adjustment as isrepresented by double-ended arrow 26. The left and right lateral sidesof frame 14 (from an occupant's point of view) are shown at 14 a, 14 b(see particularly FIGS. 1 and 2), and the front and rear sides of thisframe are shown at 14 c, 14 d respectively.

[0016] Lower sub-frame 20, also referred to herein as a mountingstructure, includes two, elongate, laterally spaced, substantiallyparallel side members 20 a, 20 b. These side members have a kind ofI-beam-like cross section, with different-width upper and lower flangesjoined by a central upright web, as shown. Members 20 a, 20 b aresuitably anchored to the aircraft frame.

[0017] Upper sub-frame 22 includes two, elongate, laterally spaced,substantially parallel side members 22 a, 22 b, each of which has thecross-sectional configuration clearly illustrated in FIG. 5. As can beseen, the lower portion of each of these side-members has a downwardlyfacing, somewhat C-shaped look. Projecting upwardly from this lowerportion is a substantially vertically disposed web which resides at thelaterally outer sides of members 22 a, 22 b. Members 22 a, 22 b areslideably mounted on members 20 a, 20 b, respectively, in lowersub-frame 20, with the C-shaped lower portions of members 22 a, 22 breceiving the upper flanges of members 20 a, 20 b, respectively.Low-friction-material shoes 28, made of a material such as ultra highmolecular weight polyethylene (UHMWPE), are interposed these fourlateral members (20 a, 20 b, 22 a, 22 b) as shown (see particularlyFIGS. 4 and 5).

[0018] As was mentioned earlier, an appropriate mechanism (not shown) isprovided for allowing a seat occupant selectively to adjust (in alockable and unlockable manner) the fore and aft positions of members 22a, 22 b on members of 20 a, 20 b.

[0019] Further included in upper sub-frame 22 are elongate, front andrear, transverse members 22 c, 22 d, respectively. These members, whichare referred to herein as web anchor members, each has a stout,cylindrical/tubular configuration, with a central strengthening webwhich is partially removed adjacent opposite ends to accommodate theinstallation of closure end caps, such as end cap 30 which is shown inFIG. 5. With specific reference to each end cap 30, each cap includes acentral, inwardly facing, hexagonal socket 30a which, in a sliding-fitfashion, receives a hexagonal nut 32 that receives a mounting bolt 34which functions to anchor one end of the associated tubular member tothe upright web in a upper sub-frame lateral member (22 a, 22 b). Across-nut-end-bolt assembly 36 is employed to capture each end capwithin an end of one of the tubular members, with each hex nut 32 beinginitially freely received in a socket 30 a prior to assembly of eachtubular member with an end of one of members 22 a, 22 b. Collectively,members 22 a, 22 b, 22 c, 22 d define what is referred to herein as arectangular, personnel support span, or region, 36 (see particularlyFIGS. 2 and 3).

[0020] The several elongate components which make up the lower and uppersub-frames in seat-structure 10 exhibit substantially no springy bendingunder circumstances where a vertical load, such as an impact/shock load,is delivered between a seat occupant and the frame of the aircraft.Rather, these components respond to such a load primarily incompression. This is an important feature of the present invention.

[0021] Suitably anchored to members 22 c, 22 d, and substantiallyentirely spanning previously mentioned rectangular region 36, ispreviously mentioned spanner web 15. Referring to FIG. 6 along withFIGS. 1-5, inclusive, web 15 is effectively a two-layer structure,including preferably an inner layer 40 and a jacketing, outer layer 42.Inner layer 40 is formed of a substantially non-stretchable strandmaterial, such a Kevlar® fabric material, which includes plural,elongate strands 40 a (see FIGS. 2, 5 and 6) that end up extending in afore-and-aft direction between upper sub-frame members 22 c, 22 d. Layer40 is preferably woven in nature, with cross fibres or strands having anorthogonal relationship. Outer jacketing layer 42 is formed preferablyof rip-stop Nylon®. FIG. 6 shows how spanner web 15 may be formed. Theseveral stages of construction are pictured in a quite self-explanatoryway from left-to-right in the three views which are presented in FIG. 6.Stitching 44 (FIGS. 2, 3 and 6) binds opposite ends of the effectivelycontinuous loop of the spanner web in final stages of construction. Thefinished “loop” has a somewhat “figure-8” (with a flattened, offsetcenter) configuration as viewed from a lateral side, or edge, of theloop. This configuration gives the spanner web a pair of opposite-end(front and rear) reverse loops 15 a, 15 b, respectively.

[0022] While this spanner web has been described in conjunction withformation from a Kevlar®-strand woven fabric material, it should beunderstood that other similar and suitable materials are and may becomeavailable made out of, for example, carbon-fiber material.

[0023] The completed spanner web is installed on sub-frame members 22 c,22 d as shown, with the installed web nominally possessing a certainmodest amount of tension whereby it does not sag between these sub-framemembers.

[0024]FIGS. 7 and 8 illustrate a somewhat modified form of spanner-webconstruction and mounting. Here, such a modified web is shownfragmentarily at 46. With regard to this modified web, the modificationsexist at the two, opposite-end reverse bends which loop around uppersub-frame members 22 c, 22 d. Specifically, at these two locations, twoadditional web layers 48, 50 have been added so that they lieintermediate previously described outer layer 42 and members 22 c, 22 dwhen the web is mounted in place. Layer 48 is joined directly to layer42, and is formed of an appropriate load-spreading material, such asPoron® 90. Layer 50 is joined to layer 48, and is preferably formed ofan acceleration-rate-sensitive material, such as any one of the specificviscoelastic materials known as CF-42, CF-45, and CF-47.

OPERATIONAL DESCRIPTION

[0025] With an occupant in seat 10, substantially the full weight ofthat occupant is borne by the spanner web. The web carries this load innon-stretching tension. From the spanner web, occupant load istransferred directly and dividedly to upper sub-frame 22 via front andrear tubular members 22 c, 22 d, respectively, which respond to suchload transfer, at least insofar as vertical load components areconcerned, in compression rather than in springy bending. From members22 c, 22 d, this divided occupant load is transferred in compression toupper sub-frame members 22 a, 22 b, through which members thistransferred load is delivered in compression through shoes 28, and lowersub-frame members 20 a, 22 b, in compression, to the aircraft frame.

[0026] In the event of a catastrophic or other vertically joltingoccurrence, G-loads delivered to an occupant through seat 10 uponinitial impact will not cause any noticeable spring-back, verticalloading to occur in any portion of seat 10. Hence, there will not occurany springy rebound in the seat frame and spanner web structure, and inparticular not any rebound of the kind that we have learned is heavilyresponsible for delivering extremely damaging, and even fatal, injuriesto a seat occupant. “Crash” tests performed with regard to the seat ofthis invention, with respect to “numbers” generated that relate toinjury causation, are remarkably low, and have proven to be,consistently and repetitively, well below established “danger”thresholds. One important key to this remarkable behavior is the factthat, in sharp distinction relative to conventional seat structures, theseat structure of this invention does not introduce a damaging reboundresponse to impact events.

[0027] Accordingly, a preferred embodiment and methodology of thepresent invention have been described and illustrated herein.Counter-intuitively, the structure and methodology of this inventionfurnish a seat support structure including spanner web structure which,by reducing almost to non-noticeablity any spring rebound action withrespect to a catastrophic vertical load imposed by a seat occupant onthe seat structure, damaging G-force transmission to that occupant issignificantly minimized. Those who are skilled in the art, after readingand reviewing the description and illustrations herein regarding thisinvention will appreciate that variations and modifications may be madewithout departing from the spirit of the invention.

We claim:
 1. A method of minimizing G-force impact injury to a personseated in a vehicle which has a non-springy vehicle frame comprisingcreating a person-seating structure which exhibits substantially novertical spring-load-type rebound to a vertical compressive shockintroduced to this structure, and following said creating, anchoring thecreated person-seating structure effectively directly to the vehicleframe.
 2. A method of minimizing G-force impact injury to person seatedin a vehicle which has a non-springy vehicle frame comprising providingperson-seating frame structure with a sub-frame whose structure respondsto seated-occupant-introduced loads in compression and without anyappreciable flexing and bending, and which includes an open span adaptedto be spanned by a web of fabric material, spanning the sub-frame spanby anchoring such a web to the sub-frame, with the web being formed withelongate material strands that are non-stretchable, and utilizing theassembled combination of the sub-frame, the span and the spanning fabricweb to react to loads introduced thereto by a seated personsubstantially without any springy response.